Pliers



Feb. 15, 1944.

J. A. DORMAN PLIERS Filed April Lil Patented Feb. 15, 1944 PLIERS I J ames A. Dorman, Washington, M6; 7 Application April24, 1942, Serial No. 440,367

4 Claims.

This invention relates generally to the class/of tools, and pertains particularly to atool of the plier type.

The primary object of the present invention is to provide an improved type of pliers having a cam operated jaw which is designed and operatively coupled with one handle in such a manner as to give a greater power or gripping force than can be obtained by the use of the ordinary type of pliers in which the two handles and two jaws are formed integrally and merely have crossed pivoted relation.

Another object of the invention is to provide an improved pliers having a cam actuated or cam powered jaw wherein the construction and relation of the jaw to the actuating handle therefor is such that the jaw is controlled by the force applied to the handle, thereby particularly adapting the tool to use as a pipe wrench or to a similar use where it is desirable that the gripping power of the tool be increased proportionately to the force applied to the handle.

The invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawing, it being understood, however, that the invention is not to be considered as limited by the specific illustration or description but that such illustration and description constitute a preferred embodiment of the invention.

In the drawing:

Figure l is a view, partly in side elevation and partly in section, of the present tool;

Figure 2 is a top edge view of the forward end of the tool;

Figure 3 illustrates the positions of the jaws in the opened tool;

Figure 4 is a section on the line 44 in Figure 1;

Figure 5 is a partial section on the line 5--5 of Figure 1.

Referring now more particularly to the 'drawing, it will be seen that the present tool comprises the two jaws l and H, the jaw l0 being integrally joined through the shank portion l2 with the rigid handle l3. 7

The jaws l0 and II are provided with the coacting toothed faces l4 and inwardly of these faces they are provided with the coacting cutting edges I which are disposed at one side of the longitudinal center of the tool and are provided for the cutting of wire or similar material.

At its inner end the jaw H, which constitutes the movable jaw of the implement, is provided with the rearwardly directed concaved camming face l6. a

At the inner or rear end also of the movable jaw ll there are formed the two spaced integral ears II which are extended transversely with respect to the jaw andwhich project rearwardly beyond the sides of the camming face l6, forming shields or side walls for the camming face. Adjacent their ends the spaced'ears are provided with pivot pin apertures l8 and inwardly of the apertures 18 the ears are provided with the short slots H] which are disposed slightly to the rear of the camming face I6.

The shank portion l2 of the fixed jaw has the slot 20 therethrough and at the forward side of this slot there is formed through the shank the pivot pin aperture 2| which is designed to align with the apertures l8 of the ears H.

The cars I! receive the shank portion ll between them so as to align the apertures l8 and 2| as stated, and a pivot pin 22 extending through the apertures pivotally couples the two jaws together.

The numeral 23 designates the movable .jaw actuating handle, or what might be termed the movable handle. The forward end of this handle has the flat head 24 which extends through the slot 20 and. is pivotally secured therein by means of the pivot pin 25 which passes through the shank l2 adjacent the forward part of the slot 20. The forward edge of the head 24 is oonvexed, as shown, to form the camming surface 26. This surface may be of approximately the same curvature as surface It, but the surfaces have contact through only a small portion of their length when the jaws are closed, as shown in Figure 1, and engage more fully when the jaws are open, as shown in Figure 3. Due to the slightly offset position of the head 24 whereby it extends through the recess 20 obliquely with respect to the shank 12, the major portion of the camming surface 26 lies to one side of the shank to have contact with the camming face It of the movable jaw.

The forward portion of the head 24 lies between the slots' IQ of the ears and the head carries, upon its two opposite side faces, the pins 21 which loosely engage in the slots l9. These pins may constitute the ends of a single pin driven through the shank, or they may be in the form of individual pins set in the side faces of the shank, whichever is found to be most satisfactory. The function of these pins is merely to open the jaw H and to keep it in contact with the camming surface 26.

The present improved pliers have the advantage over other types of pliers which are adjustable to change their mechanical force, in that no screw adjustment is employed and the jaws do not have to be first fully opened to adjust them to the object to be grasped. Thus, greater ease of manipulation is had as one hand only need be employed for the control of the jaws, and by the provision of the camming action a greater gripping power is obtained. r

1. Pliers comprising a jaw having a shank portion and a rigid handleintegral with the shank portion, said shank portion having a slot there through, a pivoted jaw 'forcoaction with the fi1'st jaw and having a pair of laterally directed ears receiving between them the shank portion of the" first jaw, a pin extending through said ears and the first jaw, said pivoted jaw having a rear- 7 wardly directed concaved camming face located between the ears, apivoted handle having an obliquely directed head portion disposed in and extending through said slot,"a pivotal connection between said head portion and the shank of the first jaw, and said head having an arcuate forward edge surface corresponding in curvature with said camming face and disposed in sliding contact "therewith.

2. Pliers as set forth in claim 1', in which said ears are provided with transversely aligned short slots extending transversely of the length of the jaw, and pins carried upon the opposite faces of said pivoted handle head and having sliding engagement in said slots.

3. Pliers as set forth in claim 1, wherein the pivot between the head of the pivoted jaw and the shank of the first jaw is substantially upon the longitudinal center of the pliers and wherein the pivot between said ears and the shank of the first jaw is disposed in advance of the pivot for saidhead and farther removed from the longitudinal center of the pliers than the first pivot.

- v 4. Pliers of the character described comprising a jaw having a rigid handle, a movable jaw, a pair of spaced ears carried by the movable jaw between which the rear part of the first jaw is located, a pivot' pin passing through the ears and the rear'portion of the first jaw, a handle pivotally attached to the first handle adjacent to the rear of the first jaw, means forming a pair of camming surfaces between the pivoted handle and the pivoted jaw'forefiecting movement of the pivoted jaw toward the first jaw when the pivoted handle is moved toward the first handle, and a couplingseparate from the camming means between the forward end of the pivoted handle and the rear portion of the pivoted jaw by which a positive opening movement of the pivoted jaw is effected upon oscillation of the pivoted handle.

. JAMES A. DORMAN. 

